Winco DPG-2145-001 - Manual (Page 36)

Manual 36526F DPG-21XX-00X Digital Controllers
Woodward 28
E
rr
o
r
Time
+E
-E
0
Integration works on
the sum of the errors
accumulated over time
The Derivative works on the
Instantaneous Rate of Change
in the amount of error
The Proportional
term's output is
unique for each
measured error
During each of the steps 3 through 6, you need to disturb the system by adding and
removing
a load from the engine to check the controller’s response to the load
transition. START WITH SMALL LOADS.
Note that without integral, a speed error may persist after a load-on load-off transition.
Therefore, during steps 3-5 you should temporarily increase the integral to get the
engine speed back to the set speed, and then reset the integral to a lower value again
while working to find good proportional and derivative values. Repeat steps 3-7 as
needed to find a Proportional value, Integral value, and a Derivative value that work
well with a variety of overall gain values and different load transients.